From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Performance comparison graph for 112° masked and 114° unmasked camshafts.
| Identifier | ExFiles\Box 182\M19\ img272 | |
| Date | 29th October 1931 guessed | |
| RM.{William Robotham - Chief Engineer} P. 31 COMPARISON OF 112° MASKED CAMSHAFT AND 114° UNMASKED CAMSHAFT OPEN EX. C.R 4.7 HIGH LIFT ROCKERS, TWIN CARBS 1+4 CHOKES MASKED SHAFT, INLET LIFT .547 EXHAUST LIFT .469 Graph Axes: B.H.P. I.H.P. R.P.M. IND. DEPN. INS. HG. B.M.E.P. Diagram C (top left): 114° SHAFT E.62448 VALVE LIFT INCREASED TO .525 C .020 CLCE EX IN 52 49 2.2 .75 Diagram A (bottom left): HIGH LIFT ROCKERS .020 CLCE A EX IN 68 44 49 21 3 11-2 Diagram B (bottom right): HIGH LIFT ROCKERS .020 CLCE B EX IN 60-3 36-3 54-4 29 5° 4° | ||